US-12620837-B2 - Method for detecting foreign object and electronic device

Abstract

An electronic device capable of transmitting and receiving wireless power may include a wireless power transfer (WPT) coil and a processor configured to be operatively connected to the WPT coil, wherein the processor may perform control to transmit a first ping signal to an external object through the WPT coil, may identify a waveform of a current or voltage measured while or after transmitting the first ping signal, may obtain a Q factor, based on the identified waveform, may control a power transmission operation by determining that the external object is a foreign object or includes the foreign object and is positioned on a center of the WPT coil when the obtained Q factor is less than a predetermined Q factor, may transmit a second ping signal to the external object through the WPT coil when the obtained Q factor is equal to or greater than the predetermined Q factor, may identify a waveform of a current or voltage while or after transmitting the second ping signal, may identify inductance measured at both ends of the WPT coil, based on the identified waveform, and may control the power transmission operation by determining that the external object is the foreign object or includes the foreign object and is positioned in a surrounding area of the WPT coil, based on the measured inductance.

Inventors

• Hyungkoo CHUNG
• Dongzo KIM
• Mincheol HA
• Yusu KIM
• Kihyun Kim
• Yunjeong NOH
• Keyic Son
• Taehyeon YU
• Kyungmin Lee

Assignees

• SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date

20260505

Application Date

20230106

Priority Date

20211207

Claims (20)

1. 1 . An electronic device capable of transmitting and receiving wireless power, the electronic device comprising: a wireless power transfer (WPT) coil; and a processor configured to be operatively connected to the WPT coil, wherein the processor is configured to: perform control to transmit a first ping signal to an external object through the WPT coil; identify a waveform of a current or voltage measured while or after transmitting the first ping signal; obtain a Q factor, based on the identified waveform; control a power transmission operation by determining that the external object is a foreign object or comprises the foreign object and is positioned on a center of the WPT coil based on the obtained Q factor being less than a predetermined Q factor; transmit a second ping signal to the external object through the WPT coil based on the obtained Q factor being equal to or greater than the predetermined Q factor; identify a waveform of a current or voltage while or after transmitting the second ping signal; identify inductance measured at both ends of the WPT coil, based on the identified waveform; and control the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned in a surrounding area of the WPT coil, based on the measured inductance.
2. 2 . The electronic device of claim 1 , wherein the processor is configured to perform control to maintain the power transmission operation by determining that the external object is not the foreign object or does not comprise the foreign object based on the measured inductance being equal to or greater than a predetermined inductance.
3. 3 . The electronic device of claim 1 , wherein the second ping signal has a higher frequency than the first ping signal.
4. 4 . The electronic device of claim 1 , wherein the processor is configured to: estimate that the external object is positioned in the surrounding area of the WPT coil based on the obtained Q factor being equal to or greater than the predetermined Q factor; measure first inductance measured at both ends of the WPT coil, based on the second ping signal; and control the power transmission operation by determining that the external object comprises the foreign object or is the foreign object and is positioned in the surrounding area the WPT coil based on the measured first inductance being less than a first predetermined inductance.
5. 5 . The electronic device of claim 1 , wherein the processor is configured to control the power transmission operation by determining that the external object comprises the foreign object or is the foreign object and is positioned on the center of the WPT coil based on the obtained Q factor being less than the predetermined Q factor.
6. 6 . The electronic device of claim 1 , wherein the processor is configured to: perform a ping operation based on determining that power loss is equal to or greater than a predetermined value during the power transmission operation with an external electronic device; maintain display of a user interface relating to charging while performing the ping operation; and control a fast charging operation to a normal charging operation based on the power transmission operation being the fast charging operation.
7. 7 . An electronic device capable of transmitting and receiving wireless power, the electronic device comprising: a wireless power transfer (WPT) coil; and a processor configured to be operatively connected to the WPT coil, wherein the processor is configured to: transmit a first ping signal to an external object through the WPT coil; identify a waveform of a current or voltage while or after transmitting the first ping signal, obtain a Q factor, based on the identified waveform; measure inductance at both ends of the WPT coil, based on the identified waveform; and control a power transmission operation by determining that the external object is a foreign object or comprises the foreign object and is positioned in a surrounding area of the WPT coil based on the obtained Q factor being equal to or greater than a predetermined Q factor and the measured inductance being less than a predetermined inductance.
8. 8 . The electronic device of claim 7 , wherein the processor is configured to control the power transmission operation by determining that the external object is not the foreign object or does not comprise the foreign object and is positioned in the surrounding area of the WPT coil based on the obtained Q factor being equal to or greater than the predetermined Q factor and the measured inductance being equal to or greater than the predetermined inductance.
9. 9 . The electronic device of claim 7 , wherein the processor is configured to control the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned on a center of the WPT coil based on the obtained Q factor being less than the predetermined Q factor.
10. 10 . The electronic device of claim 7 , wherein the processor is configured to control the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned in the surrounding area of the WPT coil based on the measured inductance being less than the predetermined inductance.
11. 11 . A foreign object detection method of an electronic device capable of transmitting and receiving wireless power using a wireless power transfer (WPT) coil, the method comprising: transmitting a first ping signal to an external object through the WPT coil; identifying a waveform of a current or voltage measured while or after transmitting the first ping signal; obtaining a Q factor, based on the identified waveform; controlling a power transmission operation by determining that the external object is a foreign object or comprises the foreign object and is positioned on a center of the WPT coil based on the obtained Q factor being less than a predetermined Q factor; transmitting a second ping signal to the external object through the WPT coil based on the obtained Q factor being equal to or greater than the predetermined Q factor; identifying a waveform of a current or voltage while or after transmitting the second ping signal; identifying inductance measured at both ends of the WPT coil, based on the identified waveform; and controlling the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned in a surrounding area of the WPT coil, based on the measured inductance.
12. 12 . The method of claim 11 , further comprising performing control to maintain the power transmission operation by determining that the external object is not the foreign object or does not comprise the foreign object based on the measured inductance being equal to or greater than a predetermined inductance.
13. 13 . The method of claim 11 , wherein the second ping signal has a higher frequency than the first ping signal.
14. 14 . The method of claim 11 , further comprising: determining that the external object is positioned in the surrounding area of the WPT coil based on the obtained Q factor being equal to or greater than the predetermined Q factor; measuring first inductance measured at both ends of the WPT coil, based on the second ping signal; and controlling the power transmission operation by determining that the external object comprises the foreign object or is the foreign object and is positioned in the surrounding area the WPT coil based on the measured first inductance being less than a first predetermined inductance.
15. 15 . The method of claim 11 , further comprising: determining that the external object is positioned on the center of the WPT coil based on the obtained Q factor being less than the predetermined Q factor; measuring second inductance measured at both ends of the WPT coil, based on the first ping signal; and controlling the power transmission operation by determining that the external object comprises the foreign object or is the foreign object and is positioned on the center of the WPT coil based on the measured second inductance being less than a second predetermined inductance.
16. 16 . The method of claim 11 , further comprising: performing a ping operation based on determining that power loss is equal to or greater than a predetermined value during the power transmission operation with an external electronic device; maintaining display of a user interface relating to charging while performing the ping operation; and controlling a fast charging operation to a normal charging operation based on the power transmission operation being the fast charging operation.
17. 17 . A foreign object detection method of an electronic device capable of transmitting and receiving wireless power using a wireless power transfer (WPT) coil, the method comprising: transmitting a first ping signal to an external object through the WPT coil; identifying a waveform of a current or voltage while or after transmitting the first ping signal; obtaining a Q factor, based on the identified waveform; measuring inductance at both ends of the WPT coil, based on the identified waveform; and controlling a power transmission operation by determining that the external object is a foreign object or comprises the foreign object and is positioned in a surrounding area of the WPT coil based on the obtained Q factor being equal to or greater than a predetermined Q factor and the measured inductance being less than a predetermined inductance.
18. 18 . The method of claim 17 , further comprising controlling the power transmission operation by determining that the external object is not the foreign object or does not comprise the foreign object and is positioned in the surrounding area of the WPT coil in case that the obtained Q factor is equal to or greater than the predetermined Q factor and the measured inductance is equal to or greater than the predetermined inductance.
19. 19 . The method of claim 17 , further comprising controlling the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned on a center of the WPT coil based on the obtained Q factor being less than the predetermined Q factor.
20. 20 . The method of claim 19 , further comprising controlling the power transmission operation by determining that the external object is the foreign object or comprises the foreign object and is positioned in the surrounding area of the WPT coil based on the obtained Q factor being less than the predetermined Q factor and the measured inductance being less than the predetermined inductance.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/KR2022/019668 designating the United States, filed on Dec. 6, 2022 in the Korean Intellectual Property Receiving Office and claiming priority to KR Patent Application No. 10-2021-0173461 filed on Dec. 7, 2021 in the Korean Intellectual Property Office and KR Patent Application No. 10-2022-0031285 filed on Mar. 14, 2022, in the Korean Intellectual Property Office, the disclosures of each of which are incorporated by reference herein in their entireties. BACKGROUND Field The disclosure relates to a method for detecting a foreign object and an electronic device. Description of Related Art An electronic device may be charged wirelessly or contactlessly using a wireless power transfer technology. The wireless power transfer technology may be a technique for charging a battery of a power reception device by wirelessly transmitting power from a power transmission device to the power reception device without connecting the power reception device and the power transmission device with a separate connector. The wireless power transfer technology may include a magnetic induction method and a magnetic resonance method, and may additionally include various types of wireless power transfer techniques. In wireless power transmission and reception between electronic devices, a safety-related accident may occur due to a foreign object interfering with power transmission. However, since a method for detecting a foreign object is determined by an electronic device transmitting external power, safety depends on the performance of the electronic device transmitting wireless power. SUMMARY In general, an electronic device may detect the position of a foreign object only when the foreign object is positioned at the center of a power transmission and reception coil. Accordingly, when the foreign object is positioned in an outer area of the power transmission and reception coil, the electronic device may not detect the foreign object. When the foreign object is object is positioned in the outer area of the power transmission and reception coil, power transmission efficiency may be reduced or heat may be generated. An electronic device capable of receiving wireless power according to an embodiment of the disclosure may provide a method of detecting a foreign object before receiving wireless power. An electronic device capable of transmitting and receiving wireless power according to various embodiments of the disclosure may include a wireless power transfer (WPT) coil and a processor configured to be operatively connected to the WPT coil, wherein the processor may perform control to transmit a first ping signal to an external object through the WPT coil, may identify a waveform of a current or voltage measured while or after transmitting the first ping signal, may obtain a Q factor, based on the identified waveform, may control a power transmission operation by determining that the external object is a foreign object or includes the foreign object and is positioned on a center of the WPT coil when the obtained Q factor is less than a predetermined Q factor, may transmit a second ping signal to the external object through the WPT coil when the obtained Q factor is equal to or greater than the predetermined Q factor, may identify a waveform of a current or voltage while or after transmitting the second ping signal, may identify inductance measured at both ends of the WPT coil, based on the identified waveform, and may control the power transmission operation by determining that the external object is the foreign object or includes the foreign object and is positioned in a surrounding area of the WPT coil, based on the measured inductance. An electronic device capable of transmitting and receiving wireless power according to various embodiments of the disclosure may include a wireless power transfer (WPT) coil and a processor configured to be operatively connected to the WPT coil, wherein the processor may transmit a first ping signal to an external object through the WPT coil, may identify a waveform of a current or voltage while or after transmitting the first ping signal, may obtain a Q factor, based on the identified waveform, may measure inductance at both ends of the WPT coil, based on the identified waveform, and may control a power transmission operation by determining that the external object is a foreign object or includes the foreign object and is positioned in a surrounding area of the WPT coil when the obtained Q factor is equal to or greater than a predetermined Q factor and the measured inductance is less than a predetermined inductance. A foreign object detection method of an electronic device capable of transmitting and receiving wireless power using a wireless power transfer (WPT) coil according to various embodiments of the disclosure may include: transmitting a first ping signal to an external object throu